Can’t Start Call from n8n – Assistant Not Found (Tried assistantId, assistant, Vapi Number, JWT, etc
Hey Vapi team — I’m trying to start a call using the /call endpoint from n8n, and I keep hitting this error:
400 - "Couldn't Get Assistant. Need Either
Here’s what I’ve tried so far:
Passed assistantId:
Also tried using "assistant": "Kylie" by name
Tried both a Twilio number (with SID and auth token) and the Vapi shared number using phoneNumberId:
Using n8n’s HTTP Request node to send the request
Set the Authorization header with both Private API Key and Public API Key
Also tried authenticating with a JWT (including orgId, token, and exp) in the Authorization header
Still getting the same error on every attempt
I’m currently on the trial plan
Can someone confirm if trial assistants need to be saved, assigned to a squad, or have special permissions to be used via backend API? Appreciate any help — I’ve been troubleshooting every angle.
Thanks
400 - "Couldn't Get Assistant. Need Either
assistant, assistantId, squad, Or squadId."Here’s what I’ve tried so far:
Passed assistantId:
Also tried using "assistant": "Kylie" by name
Tried both a Twilio number (with SID and auth token) and the Vapi shared number using phoneNumberId:
Using n8n’s HTTP Request node to send the request
Set the Authorization header with both Private API Key and Public API Key
Also tried authenticating with a JWT (including orgId, token, and exp) in the Authorization header
Still getting the same error on every attempt
I’m currently on the trial plan
Can someone confirm if trial assistants need to be saved, assigned to a squad, or have special permissions to be used via backend API? Appreciate any help — I’ve been troubleshooting every angle.
Thanks
